Cover for soaking pits



March 1964 w. A. MORTON &

COVER FOR SOAKING PITS Filed Sept. 6, 1960 I 3 Sheets-Sheet Fig.2.

INVENTOR. William A. Morton his ATTORNEYS COVER FOR SOAKING PITS FiledSept. 6, 1960 3 Sheets-Sheet 2 JNVENTOR. William A. Morfon his ATTORNEYSMarch 3, 1964 Filed Sept. 6, 1960 W. A. MORTON COVER FOR SOAKING PITSFiq. 5.

3 Sheets-Sheet 3 IN V EN TOR.

William A. Morton his ATTORNEYS.

United States Patent O 3,123,029 COVER FOR SOAKNG PITS William A.Morton, Mount Lebanon Township, Allegheny County, Pa., assignor toLoftus Engineering Corporation, Pttshurgh, Pa., a Corporation ofMaryland Filed Sept. 6, 1960, Ser. No. 54,310 1 claim. (Cl. 110-173) Thepresent invention relates generally to removable covers for top loadingfurnaces which customarily employ a sand seal between the top of thefurnace walls and the cover when in closed position. Such seal isnecessarily fractured by opening movement of the cover and must berenewed when the cover is returned to closed position. Morespecifically, the present invention resides in improvements in coverConstruction, mounting and seal maintenarce.

One frequently employed design of top charging furnace is the soakingpits employed in steel mills which receive and reheat the ingots, asstripped from the molds, preparatory to rolling. Customarily a pluralityor' such furnaces are provided in order to maintain a continuous supplyof uniformly heated ingots for rolling, and due to the high temperaturesto which the ingots are subjected, such furnaces and covers are fullyinsulated. The covers are, therefore, strongly constructed and are ofconsiderable weight. Customarily the means employed to remove suchcovers comprises individual wheeled carriages moving upon fixed tracksat the sides of said pits or furnaces. Such carriages are customarilyprovided with means which first lift the cover free of the furnaceopening and then move the cover longitudinally relative to the furnaceopening for charging the ingots into the furnace and thereafter reversethe movements of the carriage and cover to close the furnace opening.Snch wheeled carriages are not only expensive to manufacture but requirelarge amounts of electrical energy to operate them.

Conventional covers for pit furnaces have a series of alloy seal bladesextending around the periphery of the refractory cover. The refractoryportion of the cover is supported by a steel frame to which the sealblades are attached. The pit walls either support sand troughs or havetroughs formed in the top of the walls. The seal between the cover andpit proper is broken when the cover is lifted and restored when thecover is again lowered when in proper register with the sand troughs.

After the conventional cover is first lifted free above the pit walls itis moved horizontally to expose the heated ingots that they may beremoved from the furnace. In so doing the alloy seal blades on thatportion of the cover which must travel over the open furnace are exposedto the direct heat of the furnace, which in steel heating practice is inexcess of the temperature that the alloy seals will withstand. Theresult is that these alloys seal lades are sometimes very quicklydestroyed. One of the objects of this invention as may be noted from thedescription of the operation is to eliminates the end alloy seal bladesto reduce maintenance, and so supporting the sand on the end pit wallsof the urnace opening and shaping the underside of the refractoryportion of the cover that scaling of the gases within the furnace iseffected each time the cover is closed.

Another object of the present invention is to provide a simplified formof mounting for the cover, whereby movement only in a single horizontalplane provides for removal and replacement of the cover.

Another object of the invention is to provide a new and improved form ofcover having refractory surfaces effectin g the seal about the ends ofthe cover.

A further object of the invention is to provide a novel i the members 9.

3,l23,029 Patented Mar. 3, 1964 form of sand seal about the cover whichrequires only infrequent replacement and a convenient means foreffecting such renewal.

These and other objects' of the invention will be made apparent from thefollowing description and the drawing forming a part thereof, wherein:

FIG, l shows a plan view of two such carriages and covers mounted sideby side, with the cover of one furnace in closed position and the othercover removed for charging the furnace;

FIG. 2 shows a section taken on lines II-II of FIG. l, illustrating atransverse sectional view of the cover and the furnace opening;

FG. 3 shows a longitudinal section through the cover and furnace openingtaken on lines III-III of FIG. 1;

FIG. 4 shows a side levation of the cover and carriage; and

FIG. 5 shows a longitudinal section through the cover and furnaceopening, as in FIG. 3, but with the cover in partially open position.

Referring now in detail to the drawing wherein like reference charactersrefer to like parts, the soaking pits 1 are of generally conventionalConstruction having side walls 2 and end walls 3. A plurality of suchpits are usually arranged side by side. The tops of the pit side and endwalls about the pit opening are inclined downwardly relative to thehorizontal, in the direction of cover opening movement. A slope of /2"per foot has been found to be satisfactory. At each side of each pitopening is provided a suitable track means, such as 4, disposed in ahorizontal plane.

Mounted on track means 4, is the cover indicated generally by thereference character 5. This cover may be of any suitable Constructionand is shown as having a structural frame comprised of spaced sidemembers 6 connected by end members 7 and 8. The side members 6 arebraced intermediate their ends by transverse structural members such as9 extending between and connected to the members 6. The members 9terminate above the lowermost edge of the members 6 as shown in FIG. 3of the drawing. These members 9 may also be braced by the intermediatelongitudinal structural members 10, which preferably are ofsubstantially the same depth as Depending from the members 9 and 10, andfilling the space between the side members 6 and end members 7 and 8 isa suitable refractory member such as 11. Member 11 in combination withmembers 6 and 7 cooperates with the sand seals herenafter discussed toseal off the top opening of the soaking pit.

As shown in FIGS. 2 and 3, the refractory member 11 depends below endmember 8 and preferably termiuates flush with the bottom plane of endmember 7. The side members 6 of the cover depend below the bottom faceof refractory member 11 to provide side seals as hereinafter discussed.The bottom face 19 of refractory member il, as shown in FIG. 3, isdisposed in substantially parallel spaced relation to the sloping topfaces of the soaking pit side and end walls. End wall Sa at its top faceis provided with an inner inclined portion 12, an upwardly and outwardlyinclined portion 13 and a horizontal portion 14. The refractory member11 also has an inclined portion 15 disposed substantially parallel toand in spaced relation to said end wall portion 13. End wall 3 isprovided with an inclined top face 16, downwardly inclined portion 17and a horizontal face 18. As indicated by FIG. 2, each pit side wall 2has a top face 20 which is provided with a longitudinally extendingrecess 21 within which the lower ends of cover side members 6 depend.Preferably the lower ends of members 6 are provided with a downwardlyconverging portion Ga.

As shown by the drawing, the cover 5 is provided with a pair oflongitudinally spaced suitable axles 22 which extend beyond both coverside members 6. Mounted on the outer ends of said axles 22 are suitablefianged supporting wheels 2251 which bear upon the track 4. AXles 22 arejournaled in suitable bearings 220 mounted on members 6. Since the trackmeans 4 are disposed in a horizontal plane, the cover 7 will move in ahorizontal plane from closed to open position. As indicated on FIG. 1 ofthe drawing, the cover is actuated by any suitable means conventionallyindicated as motor 23 and gear reducer 24 upon a support such as plate25. The gear reducer 24 is provided with a shaft 2412 upon whose outerend is a suitable driving gear 26 engaged with a driven gear 27 Securedto the aXle 22. As shown in FIG. 1, each track means is provided with asuitable stop means 28 limiting movement of the cover into closedposition and a similar stop 29 limiting movement of the cover 5 intoopened position. The motor 23 is driven by any suitable electrical means(not shown) and preferably each track 4 is provided with a suitablywired limit switch (not shown) for cutting off power to the motor 23prior to engagement between the cover supporting wheels 22a and saidstop means.

As previously described, the track 4 upon which the cover 5 moves isdisposed in a horizontal plane and the bottom face of the refractorymember 11 of the cover which overlies the top faces of the pit openingis disposed in parallel spaced relation to said pit opening top faces.At 'the sides of the pit opening, the recesses 21 in the pit side wallsare filled with sand through which moves the cover side member portions611. This arrangement provides an adequate sand seal at the sides of thecover.

Each top face portion 16, 17 and 13 of pit end wall 3 and each top faceportion 12, 13 and 14 of pit end wall 311 are provided with a coating ofgranular refractory material S', which may be sand or other suitablematerial. The initial thickness of coating is not less than the spacingbetween said end wall top face portions and the corresponding parallelfaces of the cover refractory member 11, when the cover is in closedposition. By this means a complete seal is provided between the adjacentbottom face of the cover and the coated top faces of the pit end wallsby contact between the engaging refractory surfaces thereof when thecover moves into closed position.

Referring now to the use of the invention, the cover 5 has reciprocalmovement between closed and open positions upon the wheels 22:: movingover the track means 4 whose wheel supporting surfaces are in ahorizontal plane. By reason of the covver having linear movement in ahorizontal plane over a pit opening whose top surfaces are in a planedownwardly inclined from the horizontal and in the direction of openingmovement of the cover, the bottom surface of the cover refractory member11 has a movement of translation both horizontally and verticallyrelative to the plane of the inclined top surfaces of the pit opening.

When the cover 5 is in fully closed position as indicated in FIG. 3 ofthe drawing, the bottom face 19 of the cover refractory member 11 is inparallel spaced relation to each of the top faces of the pit end walls 3and 3:1. The coatings of sand upon inclined surface 12 of pit wall 311and the inclined surface 16 of pit wall 3' are in scaling engagementwith the adjacent surfaces of the face 19 of the cover refractory member11. Since all portions of the bottom surface 19 of refractory member 11have only linear movement in a horizontal plane to the left of FIG. 3,during opening movement, those portions of said bottom surface 19 incontact with the inclined sand coatings upon inclined pit wall topsurfaces 12 and 16 have a movement of translation away from and notparallel thereto. Thus there is no tendency for surface 19 to drag sandfrom said wall top surfaces 12 and 16 about the pit opening. However,since the top surface 18 of pit wall 3 is disposed in a horizontal planeand the adjacent portion of cover bottom surface 19 is in parallelspaced relation thereto, such latter surface will have a linear movementto the left and in contact with the sand coating upon said wall topsurface 13. At the same time all portions of the bottom surface 19 ofcover member 11 in contact with the sand coatings on surface 17 of pitwall 3 and surface 13 of pit wall 3:1, will simultaneously move to theleft and a point along the cover which when in closed position is insealing relation with the granular seal supported on the furnace nowgradually is raised above the sand coatings or seals upon surfaces 12,21 and 16. The angle of inclination of surfaces 13 and 717 and thecoacting surfaces 15a and 15 is preferably greater than the angle ofrepose of the sand, and sand pushed against surfaces 13 and 17 when thecover is closed will fall by gravity to the normal angle of repose andduring the closing movement of the cover will act as a friction cushionfor the closing action and the sand will again be pushed vertically intothe, spaces between surfaces la and 17 and 13 and 15 to re-establish theseal.

During successive opening and closing movements of the cover 5 some sandfrom the seal at the ends of the a cover may be entirely displaced fromthe top surfaces of the pit end wall 3 and 3a. Such sand may be readlyreplaced through the sand filling openings 3@ at the rear and insertingsand into said openings. At the front end of the cover the sand seal maybe readly established by inserting sand upon the wall surface 14, by awor'kman standing upon the adjacent platform 32.

Having thus described the invention in its presently` preferred form, itwill be understood that the details of Construction shown are forpurposes of illustration and not limitation. Thus those skilled in theart may modify the details of the invention without departing from theinvention as defined by the scope of the appended claim.

I claim: In a furnace having two upwardly extendng end walls and twoside walls whose tops define a substantially rectangular furnaceopening,

(a) the top of each said end walls comprising a shelflike surface, withthe shelf-like surface of one end wall disposed at a higher elevationthan that of the other,

(b) a layer of granular refractory scaling material on i each said endwall shelf-like surface,

(c) the top of each said side walls having an inclined groove thereinextending between the shelf-like surfaces of said end walls,

(d) a granular refractory sealing material in said grooves, r

(e) substantially horizontal track means extending longitudinally of theopposite sides of said opening,

, (f) a substantially rectangular cover mounted on wheels for reciprocallinear movement on said track means to cover and uncover said furnaceopening,

(g) said cover having surfaces at its opposite ends for severally matingwith said shelf-like end wall surfaces and the scaling material thereon,and

(h) the opposite sides of said cover having longitudnally extendingdepending members from one end to the other longitudinally of the doorfor severally engaging the scaling material in said inclined grooves,

said depending members being inclined' relative to the track andparallel to sai-d inclined grooves.

References Cited in the file of this patent UNITED STATES PATENTS1,044,093 Smythe Nov. 12, 1912 1,074,509 Leask Sept. 30, 1913 1,499,801Bond July 1, 1924 l,656,963 Stevens et al Jan. 24, 1928 2,039,761Weniger May 5, 1936 2,17S,668 Longenecker Nov. 7, 1939 2189280 CroftFeb. 6, 1940 2,881,942 Allbright et al. Apr. 14, 1959 UNITED STATESPATENT OFFICE CERTIFICATE l CRRECTION Patent No. 3,123,029 March 3 1964William A. Morton It is he'z'eby Certified that error appears in theabove number-ed patent req'iring correction and that the said LettersPatent should read as corrected below.

Column 4 line 24 after "rear" insert of the cover i above wall 3 byremoving the stopper 31 Signed and sealed this 14th. day of July l94(SEAL) Attest:

EST ON G. J OHNSON EDWARD J BRENNER Attesting officer Commissioner ofPatents

